Laminate and multilayer printed circuit board

ABSTRACT

A laminate capable of mounting semiconductor elements thereon; comprising an insulating layer which is constituted by a resin portion of sea-island structure and a woven reinforcement. The resin portion of sea-island structure is, for example, such that a resin as islands are dispersed in a resin as a matrix. Thus, the insulating layer exhibits a coefficient of thermal expansion of 3.0 DIFFERENCE 10 (ppm/K) in a planar direction thereof and a glass transition temperature of 150 DIFFERENCE 300 ( DEG C.). Owing to these physical properties, thermal stresses which the laminate undergoes in packaging the semiconductor elements thereon can be reduced, so that the connections of the laminate with the semiconductor elements can be made highly reliable.

This is a continuation of copending application Ser. No. 08/430,553,filed on Apr. 28, 1995 now U.S. Pat. No. 5,677,045, which is aContinuation-in-Part of application Ser. No. 08/266,821, filed Jun. 27,1994, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a laminate and a multilayer printedcircuit board on each of which semiconductor elements can be mounted.

The present invention, further, relates to a high density and multi-pinsemiconductor device and a semiconductor mounting device capable ofcoping with high speed transmission with good electric characteristicand good mounting reliability.

2. Description of the Related Art

Multilayer substrates of low thermal expansibilities include a substratehaving a ceramics core layer, a substrate with ceramics deposited on acopper foil by flame spraying, and so forth. The coefficients of thermalexpansion of these substrates are 10 (ppm/K) or less in the planardirections thereof (in the direction of each substrate within thebonding surface thereof). The ceramics-based substrates, however, areproblematic in their drillabilities in the case of formingthrough-holes. Meanwhile, regarding organic substance based substrates,it has been known that the coefficient of thermal expansion can bereduced by mixing an inorganic filler into a resin system. Thiscontrivance, however, results in enlarging the elastic modulus of thesubstrate and is not always satisfactory for attaining lower stresses.

It has heretofore been known that a lower elastic modulus can beachieved by adding a rubber type component into the resin component of alaminate material (Japanese Patent Application Laid-open No.100446/1986). In this case, a flexible substrate of excellent toughnessis provided by rendering the resin and rubber type components miscible.This contrivance is really effective to reduce the elastic modulus ofthe substrate, but it tends to enlarge the thermal expansion coefficientthereof.

It has also been known to apply to a laminate the combination of amatrix resin component and another resin component which exhibits aninferior miscibility with the matrix as represented by a so-called"sea-island structure" (a phase separation structure in which acontinuous matrix contains another phase (dispersed islands) existing inan independent state. The island portion is dispersed portion, and thesea portion is continuous matrix portion). As an example of such alaminate, there has been proposed a substrate in which a layer made ofthe resin components of the sea-island structure is formed in only thesurface of the substrate, thereby attaining a lower elastic modulus andreducing thermal stresses in the case of packaging semiconductorelements on the laminate (Japanese Patent Application Laid-open No.356995/1992). With this method, however, it is difficult to reduce thecoefficient of thermal expansion of the substrate in the planardirection thereof and it has a slight effect on the characteristics ofthe whole substrate.

Semiconductor elements have been changed to higher integration andhigher function, such as from LSI to VLSI, ULSI, and consequentlyelements become large in size, many in pins, fast in operating speed,much in consuming electric power.

To cope with more pins, it becomes practical to employ a grid arraystructure in which a connecting terminal array is provided on a mountingsurface by using a multi-layered carrier substrate.

The grid array structure employs a ball grid array structure which hasshort length connecting terminals to realize high speed signalpropagation. The ball structure as connecting terminal is effective forlower its inductance because the conductor width can be thickened. Inrecent years, in order to further increase the transmission speed, it isproposed that an organic material having low dielectric constant is usedfor the carrier substrate (U.S. Pat. No. 5,216,278).

However, since thermal expansion coefficient of organic materials areusually larger than that of semiconductor element, there is a problem inconnecting reliability due to thermal stress caused by difference ofthermal expansion coefficients between them.

SUMMARY OF THE INVENTION

The present invention has for its object to provide a laminate, amultilayer printed circuit board and a prepreg each of which exhibitslow thermal stresses owing to a small thermal expansion coefficient anda low elastic modulus, and electronics products employing any of them.

An object of the present invention is to provide a resin encapsulatedtype semiconductor device and a semiconductor mounting device with aresin encapsulated type semiconductor device having high connectingreliability in which an organic material is used as their carriersubstrates in semiconductor devices having a ball grid array structure.

In order to accomplish the aforementioned object, the present inventionconsists in the following expedients:

The first of the expedients is a laminate capable of mountingsemiconductor elements thereon; comprising an insulating layer which isconstituted by a resin portion of sea-island structure and a wovenreinforcement, and which exhibits a coefficient of thermal expansion of3.0˜10 (ppm/K) in a planar direction thereof and a glass transitiontemperature of 150˜300 (°C.).

The second expedient is a multilayer printed circuit board capable ofmounting semiconductor elements thereon; comprising at least twoinsulating layers each of which is constituted by a resin portion ofsea-island structure and a woven reinforcement, and each of whichexhibits a coefficient of thermal expansion of 3.0˜10 (ppm/K) in aplanar direction thereof and a glass transition temperature of 150˜300(°C.)

The third expedient is a laminate capable of mounting semiconductorelements thereon; comprising an insulating layer which is constituted bya resin portion of sea-island structure, an inorganic filler and a wovenreinforcement, and which exhibits a coefficient of thermal expansion of3.0˜10 (ppm/K) in a planar direction thereof and a glass transitiontemperature of 150˜300 (°C.).

The fourth expedient is a multilayer printed circuit board capable ofmounting semiconductor elements thereon; comprising at least twoinsulating layers each of which is constituted by a resin portion ofsea-island structure, an inorganic filler and a woven reinforcement, andeach of which exhibits a coefficient of thermal expansion of 3.0˜10(ppm/K) in a planar direction thereof and a glass transition temperatureof 150˜300 (°C.).

The fifth expedient is a prepreg wherein a woven reinforcement isimpregnated with a resin component; comprising the fact that said resincomponent includes a resin portion of sea-island structure, and that theprepreg after having been set exhibits a coefficient of thermalexpansion of 3.0˜10 (ppm/K) in a planar direction thereof and a glasstransition temperature of 150˜300 (°C.)

The sixth expedient is a prepreg wherein a woven reinforcement isimpregnated with a resin component; comprising the fact that said resincomponent includes a resin portion of sea-island structure and aninorganic filler at an average grain diameter of 0.1˜15 (μm), and thatthe prepreg after having been set exhibits a coefficient of thermalexpansion of 3.0˜10 (ppm/K) in a planar direction thereof and a glasstransition temperature of 150˜300 (°C.).

The seventh expedient is a memory card wherein a memory element ismounted on a circuit board by surface packaging; comprising the factthat said circuit board includes an insulating layer which isconstituted by a resin portion of sea-island structure and a wovenreinforcement, and which exhibits a coefficient of thermal expansion of3.0˜10 (ppm/K) in a planar direction thereof and a glass transitiontemperature of 150˜300 (°C.)

The eighth expedient is a computer which has a multilayer printedcircuit board capable of mounting semiconductor elements thereon;comprising the fact that said multilayer printed circuit board includesan insulating layer which is constituted by a resin portion ofsea-island structure and a woven reinforcement, and which exhibits acoefficient of thermal expansion of 3.0˜10 (ppm/K) in a planar directionthereof and a glass transition temperature of 150˜300 (°C.), and that asignal transmission delay time of said computer is 1˜15 (ns/m)

The ninth expedient is a communication equipment which has a circuitboard capable of mounting semiconductor elements thereon; comprising thefact that said circuit board includes an insulating layer which isconstituted by a resin portion of sea-island structure and a wovenreinforcement, and which exhibits a coefficient of thermal expansion of3.0˜10 (ppm/K) in a planar direction thereof and a glass transitiontemperature of 150˜300 (°C.), and that a weight of said communicationequipment is 10 (g)˜30 (kg).

The tenth expedient is an electronics equipment which has a circuitboard capable of mounting semiconductor elements thereon; comprising thefact that said circuit board includes an insulating layer which isconstituted by a resin portion of sea-island structure and a wovenreinforcement, and which exhibits a coefficient of thermal expansion of3.0˜10 (ppm/l) in a planar direction thereof and a glass transitiontemperature of 150˜300 (°C.), and that a total volume occupied by saidsemiconductor elements and said circuit board is 1˜50 (%) with respectto a volume of the whole electronics equipment.

The eleventh expedient is a laminate wherein at least one prepreg orshoot which it constituted by a resin and a woven reinforcement isstacked and bonded; comprising the that said woven reinforcement isconstructed so as to exhibit an anisotropy as a physical property, andthat said resin is in the form of a continuous layer which has asea-island structure and which prevents the layers of wovenreinforcement from coming into contact with each other.

The twelfth expedient is a laminate wherein at least one prepreg orsheet which is constituted by a resin and a woven reinforcement isstacked and bonded; comprising the fact that said woven reinforcement isconstructed so as to exhibit an anisotropy as a physical property, thatsaid resin is in the form of a continuous layer which has a sea-islandstructure and which prevents the layers of woven reinforcement fromcoming into contact with each other, and that said laminate exhibits acoefficient of thermal expansion of 3.0˜10 (ppm/K) in a planar directionthereof and a glass transition temperature of 150˜300 (°C.)

The 13th expedient is as follows. In a resin encapsulated typesemiconductor device covered with a resin encapsulating material atleast a mounting portion of a carrier substrate mounting a semiconductorelement, the mounting surface of said carrier substrate having aconnecting terminal formed of a solder ball grid, said carrier substrateis a laminated plate made of an organic material and a reinforcedmaterial, thermal expansion coefficient of the laminated plate in aplanar direction and thermal expansion coefficient of said resinencapsulating material being 3 to 10 ppm/K, the difference between bothof the thermal expansion coefficients being smaller than 3 ppm/K.

The 14th expedient is as follows. The organic material forming saidcarrier substrate is an organic material having phase separationstructure.

The present invention is characterized in that the organic materialcomposing said carrier substrate has phase separation structure, andparticularly has a low thermal expansion coefficient on a planardirection.

The thermal expansion coefficient in a planar direction in the presentinvention means the thermal expansion coefficient in the adheringsurface in a laminated plate. There are three kinds of the thermalexpansion coefficients in the adhering surface; thermal expansioncoefficient in X-direction in which a tension force acts on thereinforcing material in coating process during prepreg fabricating,thermal expansion coefficient in Y-direction intersecting with theX-direction at right angle, and thermal expansion coefficient in biasdirection inclining to the two directions at 45 degree. The magnitudesof these thermal expansion coefficients generally become as follows:thermal expansion coefficient in bias direction>thermal expansioncoefficient in Y-direction>thermal expansion coefficient in X-direction.Therefore, the effects on the reinforcing material and the laminatingadhesion in the bias direction are the smallest. The thermal expansioncoefficient in a planar direction in the present invention is defined asthe thermal expansion coefficient in the bias direction.

The elastic modulus of the organic material having phase separationstructure becomes low. Therefore, the glass cloth as low thermalexpansion component of the complex material can be increased tocontribute as a matrix against the thermal expansion coefficient in aplanar direction. Since the elastic modulus of the laminated plate issmall compared to that of a laminated plate without phase separationstructure, the thermal stress generated in the laminated plate can bedecreased.

The phase separation structure described above means a structure inwhich the matrix insulating layer is composed of two or more structuralcompositions having different components, for example, island-structuremorphology. There are two kinds of such morphology; morphology in athermodynamic stable state and morphology in a kinetic meta-stable statedue to high viscosity of the matrix.

The resin material having such a phase separation structure issubstantially effective to decrease thermal expansion coefficient and todecrease elastic modulus for the organic material of carrier substrate.Such a resin composition can he obtained by mixing or copolymerizing twoor more components having poor miscibility with each other.

The phase separation state of the phases above may be either in athermodynamic stable state or in a kinetic meta-stable state due to highviscosity of the matrix.

As for the matrix resin described above, there are thermo-set resinssuch as epoxy resin, unsaturated polyester resin, epoxy-isocyanateresin, maleimide resin, maleimide-epoxy resin, cyanate-ester resin,cyanate-ester-epoxy resin, cyanate-ester-maleimide resin, phenolicresin, diallyl-phthalate resin, urethane resin, cyanamide resin ormaleimide-cyanamide resin.

As for the organic components immiscible with the above r.sins andcapable of forming the phase separation structure, there are, forexample, a polymer of a silicon-containing compound, afluorine-containing compound and a polymer of these compounds. As forthe typical silicon-containing compounds, there are organo-siloxane andorgano-poly-siloxane having amino group, carboxyl group, epoxy group,hydroxy group, pyrimidine group, carboxylic group in end group or inside chain.

As for the typical fluorine-containing compounds, there areperfluoro-ether, poly-tetrafluoro-ethylene (PTFE), copolymer ofpoly-tetrafluoro-ethylene and perfluoro-alkylyinyl-ether (PFA),copolymer of tetrafluoro-ethylene and hexafluoro-propane (FEP),polychloro-trifluoro-ethylene (PCTFE), copolymer of ethylene andtetorafluoro-ethylene (ETFE), copolymer of ethylene andchloro-trifluoro-ethylene (ECTFE), polyvinylidene fluoride (PVDF),polyvinyl fluoride (PVF) having amino group, carboxyl group, epoxygroup, hydroxy group, pyrimidine group, isocyanate group, carboxylicgroup in end group or in side chain. The molecular weight of the abovepolymers is preferably 1000 to 1000000.

As for the encapsulating material in the present invention, there isgenerally used a molding compound having the main components of epoxyresin component, silicon group resin component, maleimide group resincomponent and melted silica filler (spherical silica particlesmanufactured by melting silica powder through spray drying method). Bychanging mixing ratio of the melted silica filler, the thermal expansioncoefficient of the encapsulating material can be adjusted.

The carrier substrate according to the present invention is capable ofproviding a ground layer inside the substrate by being constructed inmulti-wiring layer, decreasing concurrent switching noise in high speedcomputing process which will be effective for a package of a high speedsemiconductor device having clock frequency more than 100 MHz in thefuture.

A semiconductor device having a carrier substrate according to thepresent invention is high in processing speed due to low noise, lowinductance and short wiring length, and is high in mounting reliabilitythrough grid array structure of multi-pin due to low thermal stress bylow elastic modulus and low thermal expansion coefficient of carriersubstrate.

The 15th expedient is as follows. In a semiconductor mounting devicemounting on a mounting substrate at least one of resin encapsulated typesemiconductor devices covered with a resin encapsulating material atleast a mounting portion of a carrier substrate mounting a semiconductorelement, the mounting surface of said carrier substrate having aconnecting terminal formed of a solder ball grid, said carrier substrateand said mounting substrate are laminated plates made of an organicmaterial and a reinforced material, thermal expansion coefficient of thelaminated plates in a planar direction and thermal expansion coefficientof said resin encapsulating material being 3 to 10 ppm/K, the differenceamong the three of the thermal expansion coefficients being smaller than3 ppm/K.

The 16th expedient is as follows. The organic material forming saidcarrier substrate and said mounting substrate is an organic material ofphase separation structure.

The mounting substrate has a laminated plate composed of an organicmaterial for insulating layers and fiber reinforcing material such asglass cloth similar to the carrier substrate. By using an organicmaterial having phase separation structure, the thermal expansioncoefficient and elastic modulus in as planer direction can be decreasedand a semiconductor mounting device having high connecting reliabilitycan be provided. In the present invention, a solder ball grid is used asthe means for is mounting the semiconductor element to a carriersubstrate and connect to the carrier substrate and to a mountingsubstrate.

It is possible to realize high speed signal propagation by using a lowdielectric material for the mounting substrate.

The stress between the semiconductor element and the carrier substratecan be decreased by forming a multi-wiring layer on the semiconductorelement, forming bump wiring for the ball grid in the outmost layer,employing the ball grid array type and the multi-wiring layer having alow elastic modulus.

In the past, the fabricating process and the fabricating apparatus forthe semiconductor device have been complex since wire bonding method isemployed for connecting to the semiconductor element and ball grid arraystructure is employed for connecting to the mounting substrate. In thepresent invention, since the ball grid array structure is employed forconnecting to the both, the present invention has an advantage in thispoint.

Since the length of connecting wire in the ball grid array structure isshorter than that in the wire bonding method, the inductance is loweredand the processing speed is increased Further, it is easy to form themulti-pin since the terminals can be extracted from the whole surface.

As for the method of forming multi-wiring layer on the semiconductorelement, there are the sequentially multi-wiring layer method wherepatterning of insulating layer and vapor deposition are alternatinglyperformed, the multi-layer method of substrates having wiring film andso on, but it is not limited to these.

The present invention can be applied to the semiconductor element whichis formed IC, LST such as memory, logic, gate array, custom, powertransistor on a semiconductor wafer such as Si, GaAs and has connectingterminals such as lead terminals and bump terminals.

In the present invention, a "semiconductor element" is an element inwhich an IC (integrated circuit) or LSI (large-scale integrated circuit)including, for example, a memory, a logic circuit, a custom IC or/and apower transistor is formed on a wafer made of a semiconductor such as Si(silicon) or GaAs (gallium arsenide), and which has terminals forconnecting the IC or LSI to leads, bumps etc. The elements shallinclude, not only bare chips, but also packaged chips in the state inwhich the element is covered or encapsulated with a resin or ceramics,in the state in which the element has been subjected to tape automaticbonding (TAB), and so forth.

Also in the present invention, a "laminate" is a structural product ormember which is fabricated in such a way that at least one piece ofprepreg, sheet or the like which has been obtained by impregnating awoven reinforcement with a resin component is layered, and that thelayer is pressed, bonded and molded. By way of example, the wovenreinforcements include a piece of cloth or sheet which in made ofinorganic type fiber glass of (such as E glass (electrical glass), Sglass (structural glass), D glass (dielectric glass) or Q glass (quartzglass)), titanium or the like; a piece of cloth or sheet which is madeof organic type fiber of polyamide, polyamideimide, polyimide, aliquid-crystalline polymer, aromatic polyamide or the like; a piece ofcloth which is made of surface insulated carbon fiber; and a piece ofcloth or sheet which is made of at least two kinds of fiber selectedfrom among the inorganic type fiber, organic type fibers and surfaceinsulated carbon fibers mentioned above. Besides, for such a purpose ofenhancing an electromagnetic-wave shielding property, a radiationresistance or a mechanical strength or bestowing an electricconductivity, it is possible to use a piece of cloth or sheet which ismade of surface insulated metal fiber or a piece of cloth or sheet whichis made of a composite system consisting of surface insulated metalfiber and at least one kind of fiber selected from among inorganic typefiber, organic type fiber and surface insulated carbon fiber.

Also in the present invention, a "multilayer printed circuit board" is awired circuit board for mounting semiconductor elements thereon, whichis formed with at least two wiring layers that are connected by means ofthrough-holes etc. Examples of the wiring layers bear circuits which areformed from foils of metals or by plating with or vacuum evaporation ofmetals. The metals are copper, silver, gold, aluminum, chromium,molybdenum, tungsten, etc. Especially, copper is preferable, and thecopper foil is recommended.

Further, a resinous varnish for impregnating the woven reinforcement inthe present invention accounts for about 30˜90 (weight-%) in terms ofthe solid matter content of the varnish with respect to the total weightof both the varnish and the woven reinforcement (that is, the wovenreinforcement accounts for about 70˜10 (weight-%) with respect to thetotal weight). When the proportion of the varnish is smaller, a goodprepreg or film is difficult to obtain. On the other hand, when theproportion of the varnish is larger, it is difficult to make thecoefficient of thermal expansion of the laminate in the planar directionthereof fall within a range of 3.0˜10 (ppm/K). Besides, the effect ofreinforcing the laminate decreases.

The laminate according to the present invention is well suited to wiringuses such as, for example, a flexible wiring circuit board and aninsulating film to intervene between circuits. By way of example, theflexible wiring circuit board is manufactured as stated below.

First, a piece of glass cloth is impregnated with a varnish which hasbeen prepared by dissolving a resin composite in an organic solvent.Subsequently, while the solvent is vaporized in a drying oven, a settingreaction is somewhat advanced to form a prepreg at B-stage (in thesemi-set state in which the prepreg melts when heat is applied thereto).At the next step, metal foils such as copper foils or aluminum foils aresuperposed on both the surfaces of the prepreg so as to sandwich theprepreg therebetween. Alternatively, such a metal foil is superposed ononly one surface of the prepreg. In this state, each metal foil isbonded by thermocompression, and the impregnating resin composite is setat the same time. Next, the surface of the metal foil (copper foil) iscoated with resist ink in the shape of a circuit, and the resist ink isdried. Next, the parts of the copper foil except the circuit are etchedwith, e. g., an aqueous solution of ferric chloride. Subsequently, usingan organic solvent such as methylene chloride, the resist ink isremoved, and the resulting structure is washed. Lastly, the resultingstructure is dipped into a soldering bath so as to stick solder topertinent parts. Then, the circuit is finished.

For such intended uses, the flexible substrate or flexible circuit boardof the present invention is generally put on the market in the semi-setstate (as the prepreg) or in the set state after the thermocompressionbonding of the metal foil or foils. The flexible substrate or circuitboard in the present invention shall include articles in both thesemi-set state and the set state.

Incidentally, the multilayer printed circuit board according to thepresent invention can also be fabricated as stated below. Aprinted-wiring circuit board already formed with a circuit is coatedwith a varnish prepared by dissolving a resin component in a solvent.Subsequently, while the solvent is vaporized in a drying oven, thevarnish is somewhat set into the B-stage (into the semi-set state).Thereafter, a metal foil such as copper foil or aluminum foil issuperposed on the outer surface of the semi-set resin component, andthermocompression is carried out to bond the metal foil and set theresin component. Further, another circuit is formed by the necessarysteps of the method explained above.

In the present invention, the impregnation of a woven reinforcement witha resin can be effected in such a way that a resin solution (varnish) isapplied to the woven reinforcement once or a plurality of times by theuse of a conventional impregnating-and-coating machine of horizontaltype or/and vertical type. Alternatively, the impregnating process canbe performed by coating one surface or both surfaces of the wovenreinforcement with the resin. Further, the impregnating process can beperformed in such a way that a solid resin sheet is superposed on thewoven reinforcement beforehand, and that the resulting wovenreinforcement is heated and/or molded. If a prepreg or the impregnatingsheet after having been dried is tacky, a mold releasing sheet can beused voluntarily at a suitable step. Usable as the mold releasing sheetis cellulosic paper or film coated with a mold releasing agent,polypropylene film, polyvinyl alcohol film, or the like.

In the present invention, a "resin portion of sea-island structure" ismade from a resin composite which consists of at least two kinds ofsubstances (e. g., a resin and a compound, or resins) being inferiorlymiscible to each other, or from a resin composite which contains a resinof phase separation type, such as a polymer produced by copolymerizingcomponents of inferior miscibility. In the resin composite, onecomponent should desirably have a lower elastic modulus than the othercomponent or components. The resin composite to be selected and used isa composite which has the sea-island structure and in which at least oneof components conjointly employed is immiscible with the other componentor components.

Mentioned as the resins of the resin composites are variousthermosetting resins, for example, an epoxy resin, an unsaturatedpolyester resin, an epoxy--isocyanate resin, a maleimide resin, amaleimide--epoxy resin, a cyanate ester resin, a cyanate ester--epoxyresin, a cyanate ester--maleimide resin, a phenolic resin, adiallylphthalate resin, an urethane resin, a cyanamide resin and amaleimide--cyanamide resin.

By way of example, silicon-containing compounds, fluorine-containingcompounds, and the polymers of these compounds are mentioned as thecompounds and resins which are immiscible with the aforementionedthermosetting resins and which form the sea-island structures when mixedwith these thermosetting resins. Typical examples of thesilicon-containing compounds are organosiloxane and organopolysiloxaneeach of which has at its terminals or its side chains, functional groupssuch as amino groups, carboxyl groups, epoxy groups, hydroxyl groups,pyrimidinyl groups or carboxylic groups. Typical examples of thefluorine-containing compounds are perfluoroether, PTFE(polytetrafluoroethylone), PFA (tetrafluoroothylene perfluoroalkyl vinylether copolymer), FEP (tetrafluoroethylene hexafluoropropene copolymer),PCTFE (polychlorotrifluoroethylene), ETFE (ethylene tetrafluoroethylenecopolymer), ECTFE (ethylene Cchlorotrifluoroethylene copolymer), PVDF(polyvinylidene difluoride) and PVF (polyvinyl fluoride) each of whichhas at its terminals or its side chains, functional groups such as aminogroups, carboxyl groups, epoxy groups, hydroxyl groups, pyrimidinylgroups, isocyanic groups or carboxylic groups. Each of the polymers ofthe specified compounds should preferably have a molecular weight of 10³˜10⁶. Such a polymer is effective to lower the elastic modulus.

In the present invention, the aforementioned resin composites of highheat resistances are especially favorable in order that the insulatinglayer of a laminate or a multilayer printed circuit board, a prepreg,etc. may exhibit glass transition temperatures falling within a range of150˜300 (°C.) (the reasons for the specified range will be explainedbelow). Besides, in the present invention, the aspect of theimmiscibility may be either of a nonreactive type or a reactive type,but the reactive type is favorable from the viewpoint of bestowing thehigh heat resistances. By way of example, in the case of a resincomposite which consists of an epoxy compound and a silicon-containingcompound, the silicon-containing compound and the epoxy compound whichhave groups being reactive with epoxy groups or hydroxyl groups can bepreviously reacted in a solution at the preparation of a varnish. Onthis occasion, it is also possible to add a setting agent, an inorganicfiller and/or a coupling agent.

In the present invention, the glass transition temperature of theinsulating layer should preferably fall within the range of 150˜300(°C.). In the case of a glass transition temperature below 150 (°C.), itbecomes difficult to satisfactorily clear the reliability tests (forexample, a high-temperature shelf test and a heat cycle test) of theproduct such as the laminate or the multilayer printed circuit board. Onthe other hand, in the case of a glass transition temperature above 300(°C.), the bestowal of the flexibility is difficult, so that theproblems of cracking and inferior molding characteristics are involvedin the product.

Further, in the present invention, the coefficient of thermal expansionin the planar direction should preferably fall within a range of 3.0˜10(ppm/K). The coefficient of thermal expansion of a semiconductor element(for example, made from silicon) is 3.0˜4.0 (ppm/K). Also, thecoefficient of thermal expansion of an encapsulating resin in aresin-molded semiconductor device is, only slightly greater than thevalue of silicon. In order to enhance the reliability of the connectionsbetween the semiconductor element and a laminate (or a multilayerprinted circuit board), it is effective to reduce thermal stresses whicharise between both the members or articles. To this end, the differencebetween the thermal expansion coefficients of the laminate and thesemiconductor element can be rendered small in such a way that thecoefficient of thermal expansion of the laminate (or the multilayerprinted circuit board) in the planar direction thereof is brought intothe range of 3.0˜10 (ppm/K). Moreover, since the construction of themultilayer printed circuit board according to the present invention doesnot include ceramics as its constituent, it can lower the coefficient ofthermal expansion Accordingly, the following effects are brought forth:

(1) The multilayer printed circuit board exhibits a superiordrillability.

(2) The connection reliability of through-holes in the multilayerprinted circuit board is high owing to the superior close adhesion ofthe circuit board with a plated metal.

(3) The multilayer printed circuit board can be made lighter in weight.

(4) Since a lower elastic modulus can be attained simultaneously withthe lower coefficient of thermal expansion, a large number of electricalparts having different thermal expansion coefficients can be mounted onthe identical surface of the multilayer printed circuit board. Thedifferences of the thermal expansion coefficients can be covered orhidden by the lower elastic modulus.

(5) A substrate or circuit board of large area can be manufactured bythe same techniques as in the prior art.

According to the present invention, various electrical parts such assemiconductor elements can be mounted by surface packaging by employinga circuit board which is constituted by a resin portion and a wovenreinforcement, the resin portion having a sea-island structure andexhibiting a coefficient of thermal expansion of 3.0˜10 (ppm/K) in aplanar direction thereof, as well as a glass transition temperature of150˜300 (°C.). Thus, the circuit board is superior in drillability to aceramics-containing substrate which is a prior-art substrate of lowthermal expansion for the surface packaging, and it is very effectivefor the reliability of through-holes because the close adhesion thereofwith a plated metal is more intense than that of ceramics. In general, aceramics-based circuit board is less bondable with a resin, and ittherefore poses a problem with regard to the reliability of theinterface between the circuit board and the resin.

In contrast, such an interface of different phases does not exist in thecircuit board according to the present invention. It is accordinglypossible to provide a memory card of high reliability. Moreover, thecircuit board according to the present invention does not containceramics, and the sea-island structure of its resin portion results in alower elastic modulus compared with an unmodified state. Therefore, evenwhen various electrical parts having unequal thermal expansioncoefficients are to be mounted together on the circuit board, thermalstresses which arise at a mounting step are of small magnitude. It isaccordingly possible to provide a multifunctional memory card ofsuperior connection reliability.

Besides, the thermal expansion coefficient of a thin package forsemiconductor elements of high integration density is nearly equal tothat of silicon and is 6 (ppm/K) or so. The semiconductor elements ofhigh integration density having low thermal expansion coefficients aretherefore permitted to be mounted densely by surface packaging while theconnection reliability is kept high, by employing a circuit board whichis constituted by a resin portion and a woven reinforcement, the resinportion having a sea-island structure and exhibiting a coefficient ofthermal expansion of 3.0˜10 (ppm/K) in a planar direction thereof, aswell as a glass transition temperature of 150˜300 (°C.). Thus, signaltransmission distances can be shortened, and a computer of higharithmetic processing speed in which signal transmission delay times are1˜15 (ns/m) can be provided. Moreover, since a reduced size and alightened weight are attained by the dense packaging, a computer ofsuperior portability can be provided.

According to the present invention, a reduced size and a lightenedweight of 10 (g)˜30 (kg) can be attained to provide a communicationequipment of superior portability in such a way that electrical partssuch as semiconductor elements are mounted at a high integration densityby surface packaging, by employing a circuit board which is constitutedby a resin portion and a woven reinforcement, the resin portion having asea-island structure and exhibiting a coefficient of thermal expansionof 3.0˜10 (ppm/K) in a planar direction thereof, as well as a glasstransition temperature of 150˜300 (°C.). Typical examples of thecommunication equipment are a portable telephone set and a portableradio equipment. Further, the sea-island substrate is lighter in weightthan a ceramics-containing substrate. Still further, compared with theelastic modulus of the ceramics-containing substrate or an unmodifiedsubstrate, that of the sea-island substrate is lowered considerably.Therefore, even when various electrical parts having unequal thermalexpansion coefficients are to be mounted together on the circuit board,thermal stresses which arise at a mounting step are of small magnitude,and a communication equipment of superior connection reliability can beprovided. Accordingly, multifarious communication equipments can befabricated in accordance with purposes.

According to the present invention, it is possible to provide a carelectronics equipment including electrical parts such as semiconductorelements, which equipment can reduce the occupying volume of itspackaging portion (concretely, a total volume to be occupied by thesemiconductor elements and a circuit board can be made 1˜50 (%) withrespect to the volume of the whole electronics equipment) and can endurea high-temperature and high-humidity environment such as an engine room,in such a way that the electrical parts such as semiconductor elementsare mounted at a high integration density by surface packaging, byemploying the circuit board which is constituted by a resin portion anda woven reinforcement, the resin portion having a sea-island structureand exhibiting a coefficient of thermal expansion of 3.0˜10 (ppm/x) in aplanar direction thereof, as well as a glass transition temperature of150˜300 (°C.). Typical examples of such a car electronics equipment arean engine control device and a navigation device. It is necessary forthese devices to be installed in limited places having severeenvironmental conditions. To this end, the equipment which employs thecircuit board constituted by the resin portion of the sea-islandstructure can achieve a reduced size by the dense packaging. Moreover,since the circuit board does not contain any ceramics material, it hasfew interfaces of different phases and exhibits a superior connectionreliability. Accordingly, the circuit board is well suited for use inthe field of car electronics.

As for the carrier substrate according to the present invention, alaminated plate composed of organic material and fiber reinforcingmaterial such as glass cloth is used. The laminated plate can beobtained by laminating, heating and pressing prepreg sheets of the fiberreinforcing material impregnated with resin component.

As for the above reinforcing materials, there are cloth or sheet made ofnon-organic fiber such as glass (E-glass, S-glass, D-glass, Q-glass),titanium and so on; cloth or sheet made of polyamide, polyamideimide,polyimide, liquid-crystal polymer, aromatic amide; cloth or sheet madeof surface insulated carbon fiber or complex material of these.

As for the mounting substrate, it is preferable to use the same materialas used for the carrier substrate.

There are two methods of jointing the semiconductor element and thecarrier substrate in the present invention. One is a method where theterminals formed on one side of the surface of the semiconductor elementand the pads formed on the surface of the carrier substrate to mount theelement are connected with wire bonding. However, more effective methodis that pad array structure is formed on the semiconductor element, andsaid pad array structure and the pad array structure formed on thesurface of the carrier substrate to mount the element are connected withbump. This method provides good signal propagation characteristicbecause of short connection length and good multi-pin capability becauseof usability of the whole surface of the element.

In order to form pad array structure on the semiconductor element,multi-wiring structure is formed on the semiconductor element. Since theorganic material provided as the multi-wiring structure generally has alow dielectric constant comparing to non-organic materials, speed ofsignal propagation can be made fast. Further, since the elastic modulusis low and has a stress modulating effect, it is possible to keepconnecting reliability even using rigid bump comparing to wire. From thestandpoint of workability and thermal resistivity, it is preferable toemploy, for example, polyimide, epoxy resin, cyanate-bis-maleimide resinand so on.

As for various conductive films, copper, silver, aluminum, molybdenumand so on may be used. However, from the standpoint of high speedtransmission, reliability and cost, copper in preferable.

In operation, in a laminate which has a resin and a reinforcement, thepresent invention puts the components of a resin composite into asea-island structure, namely, a phase separation structure, whereby thethermal expansion coefficient and elastic modulus of the resin compositecan be simultaneously reduced. As an example of a mechanism for themanifestation of the phase separation structure, in a case where thephase separation resin of the resin composite has an island structure oflow elastic modulus, the resin of the resin composite as a matrix layerwill have its elastic modulus reduced owing to a moldability added bythe island modulus reduced owing to a moldability added by the islandparts of the island Structure. Regarding the coefficient of thermalexpansion of the resin composite in the planar direction of thelaminate, it is considered that the thermal expansion of the matrixresin will crush the island parts, with the result that the thermalexpansion of the whole resin composite will decrease apparently. Otherphase separation structures can simultaneously reduce both thecharacteristics through various manifestative mechanisms.

Not all of the manifestative mechanisms have yet been satisfactorilymade clear.

In the present invention, the thermal expansion coefficients of thecarrier substrate and the encapsulating material can be effectivelydecreased by using materials having thermal expansion coefficientswithin the range of 3 to 10 ppm/K both in a planar direction of thecarrier substrate and in the encapsulating material. As for the carriersubstrate, the characteristics of low elastic modulus and low thermalexpansion coefficient can be obtained by using glass cloth or the likeas a reinforcing material and by using a laminated plate having phaseseparation structure as a matrix organic material. Thereby, thegenerated thermal stress can be decreased and the mounting reliabilitycan be substantially improved.

Further, it is possible to provide a structure having further highconnecting reliability by controlling the thermal expansion coefficientof each material including the substrate mounting semiconductor device.

Furthermore, it is possible to attain an improved electriccharacteristic suitable for high speed propagation and a multi-pinstructure by providing multi-wiring layer on the semiconductor elementand by performing bump connection of the multi-wiring layer to thecarrier substrate using a grid array structure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a model diagram showing the section of a laminate according tothe present invention;

FIG. 2 is a model diagram showing the section of a laminate in the priorart;

FIG. 3 is a model diagram showing the section of another laminate in theprior art;

FIG. 4 is a schematic cross-sectional view of a semiconductor device inEmbodiments 10 and 11;

FIG. 5 is a schematic cross-sectional view of a semiconductor device inEmbodiments 12 and 13; and

FIG. 6 is a schematic cross-sectional view of a semiconductor device inEmbodiments 14 and 15.

PREFERRED EMBODIMENTS OF THE INVENTION

Now, the present invention will be described in detail in conjunctionwith examples.

Example 1

88 parts (by weight) of phenol-novolak resin (trade name "XL225-3L",produced by Mitsui Toatsu Chamicals, Inc.) as a setting agent and 10parts (by weight) of amine-modified dimethylsiloxane ("PS51311", ChissoCorporation) as a component of low elastic modulus were added to 100parts (by weight) of epoxy compound ("EXA-1514", Dai-Nippon Ink andChamicals, Inc.) in methyl ethyl ketone. Thus, a varnish which had asolid matter content of 50 (weight-%) was prepared. A piece of E-glass(electrical glass) cloth 100 (μm) thick was impregnated and coated withthe varnish, and then dried at 120 (°C.) for 10 (min) so as to removethe solvent. Thus, a piece of prepreg was obtained. The resin content ofthe obtained prepreg was 70 (weight-%).

Copper foils (each being 18 (μm) thick) were respectively superposed onboth the surfaces of the obtained prepreg, and the resulting structurewas pressed under heat by a press. Thus, a laminate was obtained. ASpressing conditions on this occasion, two-stage reactions at 130 (°C.)for 30 (min) and at 180 (°C.) for 60 (min) were performed, and apressure of 20 (kg/cm²) was held. The copper foil peeling strength ofthe obtained laminate, and the thermal expansion coefficient of thelaminate in the planar direction thereof after having etched the copperfoils were evaluated by the TMA (Thermal Mechanical Analyzer) method.Besides, in order to measure the elastic modulus of the resin portion ofthe laminate, resin powder was scratched off the prepreg, and a resinsheet was fabricated from the resin powder under the same pressingconditions as those of the laminate. The sample of the resin sheet hadits elastic modulus at room temperature evaluated by a viscoelasticmeasurement.

Example 2

Resin components were prescribed in such a way that 55 parts (by weight)of phenol-novolak (trade name "H100", produced by Hitachi Chemical Co.,Ltd.) as a setting agent and 15 parts (by weight) of epoxy-modifiedpolydimethylsiloxane ("SF8413", Toray Silicone Co., Ltd.) as a componentof low elastic modulus were added to 100 parts (by weight) of epoxycompound ("YX4000H", Yuka Shell Kabushiki-Kaisha). On this occasion, thesetting agent and the component of low elastic modulus were reacted at90 (°C.) for 30 (min) in methyl isobutyl ketone beforehand as apre-reaction, and the resulting solution was cooled down to roomtemperature. Thereafter, the epoxy compound was added into the cooledsolution. Thus, a varnish which had a solid matter content of 50(weight-%) was prepared. A piece of S-glass (structural glass) cloth 70(μm) thick was impregnated and coated with the prepared varnish, andthen dried at 140 (°C.) for 10 (min) so as to remove the solvent Thus, apiece of prepreg was obtained.

A laminate and a resin sheet were fabricated from the obtained prepregby the same methods as in Example 1, and their characteristics weresimilarly estimated.

Example 3

Resin components were prescribed as consisting of 100 parts (by weight)of maleimide compound (bis(4-maleimidophenyl) methane, produced byMitsui Toatsu Chamicals, Inc.), 38 parts (by weight) of amine compound(2, 2-bis(4-(4-aminophenoxy) phenyl) propane, Wakayama Fine ChemicalCo.) and 5 parts (by weight) of amine-modified polydimethyleiloxane(trade name "SF84181", Toray Silicone Co., Ltd.). On this occasion,pre-reactions were so performed that 50 parts (by weight) of themaleimide compound and the amine-modified polydimethylsiloxane werereacted in dimethylformamide at 110 (°C.) for 20 (min), and that theremaining 50 parts (by weight) of the maleimide compound and the aminecompound were added into the resulting solution and were reacted for 20(min). Thus, a varnish which had a solid matter content of 40 (weight-%)was prepared. Further, 20 parts (by weight) of fused silica filler (atan average grain diameter of 10 (μm)) were mixed and dispersed into theprepared varnish. A piece of D-glass (dielectric glass) cloth 80 (μm)thick was impregnated and coated with the resulting varnish, and thendried at 140 (°C.) for 5 (min) and at 145 (°C.) for 5 (min) so as toremove the solvent. Thus, a piece of prepreg was obtained.

A laminate was fabricated from the obtained prepreg by a method similarto that in Example 1, and its characteristics were similarly estimated.The molding conditions of the laminate were 130 (°C.) for 30 (min) and200 (°C.) for 60 (min).

Example 4

Resin components were prescribed in such a way that 72 parts (by weight)of orthocresol novolak (trade name "OCN7000", produced by Nihon KayakuKabushiki-Kaisha) as a setting agent and 10 parts (by weight) ofboth-terminal ccarboxylic acid-modified perfluoroether ("ZDIAC-2000",Monte Ferrous Inc.) as a component of low elastic modulus were added to100 parts (by weight) of epoxy compound ("YX4000H", Yuka ShellKabushiki-Kaisha). On this occasion, 1 part (by weight) of imidazole("2E4Mz", Shikoku Kasei Kabushiki-Kaisha) was added as a settingaccelerator. Using acetone as a solvent, a varnish which had a solidmatter content of 60 (weight-%) was prepared. A piece of polyamide cloth70 (μm) thick was impregnated and coated with the prepared varnish, andthen had the solvent removed by drying stages at 110 (°C.) for 10 (min)and at 120 (°C.) for 15 (min). Thus, a piece of prepreg was obtained.

A laminate was fabricated from the obtained prepreg by a method similarto that in Example 1, and its characteristics were similarly estimated.The molding conditions of the laminate were 130 (°C.) for 30 (min) and200 (°C.) for 60 (min).

Comparative Example 1

A laminate and a resin sheet, each of which included a homogeneous resinportion having no sea-island structure, were fabricated using thematerials of Example 1 except polydimethylsiloxane, that is, using theepoxy compound and the phenolic setting agent. The characteristics ofthe laminate and the resin sheet were estimated.

Comparative Example 2

A laminate and a resin sheet, each of which included a homogeneous resinportion having no sea-island structure, were fabricated using thematerials of Example 3 except polydimethylsiloxane, that is, using themaleimide compound, the amine compound and the fused silica filler. Thecharacteristics of the laminate and the resin sheet were estimated.

Further, element packages in the number of 100 were soldered by surfacepackaging onto each of printed-wiring circuit boards in each of which apredetermined circuit was formed on the laminate covered with the copperfoils as explained in Example 1 (in other words, the element packageswere mounted on both the surfaces of each of the printed-wiring circuitboards by soldering). The soldering was carried out by heating-reflowwhich utilized a far-infrared heater. Each of the samples of packagedarticles was tested for 100 cycles in conformity with the MIL (militaryspecification and standards), and the number of defects of solderedconnection parts after the end of the test was counted. The measuredcharacteristics of the above examples including the number of thedefective soldered connection parts are listed in Table 1 below:

                  TABLE 1                                                         ______________________________________                                               Coeff. of                                                                     Inplane           Glass     Number of                                         thermal Elastic   transition                                                                              Defective                                         expansion                                                                             modulus   temperature                                                                             parts (in                                         (X 10.sup.6 /K)                                                                       (kg · f/mm.sup.2)                                                              (° C.)                                                                           100 parts)                                 ______________________________________                                        Example 1                                                                              9.2       295       156     0                                        Example 2                                                                              8.7       280       175     0                                        Example 3                                                                              7.2       300       285     0                                        Example 4                                                                              6.5       320       173     0                                        Comp. Ex. 1                                                                            12.5      370       155     11                                       Comp. Ex. 2                                                                            11.5      450       285     17                                       ______________________________________                                    

Example 5

FIG. 1 illustrates the construction of a laminate according to thepresent invention.

The laminate can be fabricated by stacking and bonding two pieces ofprepreg each of which is obtained in such a way that a wovenreinforcement 1 is impregnated with a resin portion 2 having asea-island structure and is then dried. In the construction, the wovenreinforcement 1 exists entirely in the planar direction of the laminate.Therefore, the effect of reducing the thermal expansion coefficient ofthe laminate in the planar direction thereof can be utilized to theutmost on the basis of the sea-island structure. Incidentally, numeral 3in FIG. 1 designates a dispersed (island) phase.

Since an organic resin matrix constituting the resin portion 2 of thesea-island structure is continuously existent penetrating thereinforcement members 1, the laminate is free from the problem ofbonding at the interface between different phases in a compositematerial.

Comparative Example 3

FIG. 2 illustrates the construction of a laminate in the prior art.

The construction is very effective in reducing the thermal expansioncoefficient of the laminate in the planar direction thereof. In thisconstruction, however, a resin matrix which constitutes a resin portion2 of sea-island structure including islands 3 does not continuouslypenetrate reinforcement members 1. Therefore, the laminate is liable topose the problem of bonding at the interface between different phases,and so forth.

Comparative Example 4

FIG. 3 illustrates the construction of a laminate in the prior art.

In the construction, a woven reinforcement 1 exists in the form ofindependent particles, so that the whole laminate exhibits an isotropy.It is therefore impossible to make the most of the effect of reducingthe thermal expansion coefficient of the laminate, in the planardirection thereof. Herein, the effect is based on the interactionbetween a resin matrix and islands 3 which form a resin portion 2 ofsea-island structure.

Examples 6˜8

88 parts (by weight) of phenol-novolak resin (trade name "XL225-3L",produced by Mitsui Toatsu Chamicals, Inc.) as a setting agent, and 10parts, 20 parts and 50 parts (by weight) of amino-group-terminalperfluoroether type compound (produced by Mitsui FluorochemicalKabushiki-Kaisha) as a component of low elastic modulus wererespectively added to 100 parts (by weight) of epoxy compound("EXA-1514", Dai-Nippon Ink and Chamicals, Inc.) in methyl ethyl ketone.Thus, three kinds of varnish each of which had a solid matter content of50 (weight-%) were prepared. Pieces of E-glass (electrical glass) clotheach being 100 (μm) thick were respectively impregnated and coated withthe varnish samples, and then dried at 120 (°C.) for 10 (min) so as toremove the solvent. Thus, pieces of prepreg were obtained. The resincontent of each of the obtained prepreg pieces was 70 (weight-%). Copperfoils (each being 18 (μm) thick) were respectively superposed on boththe surfaces of each of the obtained prepreg pieces, and the resultingstructures were respectively pressed under heat by a press. Thus,laminates were obtained. As pressing conditions on this occasion,two-stage reactions at 130 (°C.) for 30 (min) and at 180 (°C.) for 60(min) were performed, and a pressure of 20 (kg/cm² was held. The copperfoil peeling strengths of the obtained laminates, and the thermalexpansion coefficients of the laminates in the planar directions thereofafter having etched the copper foils were respectively evaluated by theTMA (Thermal Mechanical Analyzers method. Besides, in order to measurethe elastic moduli of the resin portions of the laminates, powderyresins were respectively scratched off the corresponding prepreg pieces,and resin sheets were respectively fabricated from the powdery resinsunder the same pressing conditions as those of the laminates. Thesamples of the resin sheets had their elastic-moduli at room temperatureevaluated by viscoelastic measurements, respectively.

Example 9

Resin components were prescribed in such a way that 55 parts (by weight)of phenol-novolak (trade name "H100", produced by Hitachi Chemical Co.,Ltd.) as a setting agent and 15 parts (by weight) ofcarboxyl-group-terminal perfluoroether type compound (produced by MitsuiFluorochemical Kabushiki-Kaisha) as a component of low elastic moduluswere added to 100 parts (by weight) of epoxy compound ("YX4000H", YukaShell Kabushiki-Kaisha). On this occasion, the setting agent and thecomponent of low elastic modulus were reacted at 90 (°C.) for 30 (min)in methyl isobutyl ketone beforehand as a pre-reaction, and theresulting solution was cooled down to a room temperature. Thereafter,the epoxy compound was added into the cooled solution. Thus, a varnishwhich had a solid matter content of 50 (weight-%) was prepared. A pieceof S-glass (structural glass) cloth 70 (μm) thick was impregnated andcoated with the prepared varnish, and then dried at 140 (°C.) for 10(min) so as to remove the solvent. Thus, a piece of prepreg wasobtained.

A laminate and a resin sheet were fabricated from the obtained prepregby the same methods as in Examples 10 6˜8, and their characteristicswere similarly estimated.

Likewise to Examples 1 thru 4 and Comparative Examples 1 and 2, packagedarticles were fabricated for Examples 6 thru 9, and the samples thereofwere tested as to the defects of soldered connection parts.

The measured characteristics of Examples 6 thru 9 are listed in Table 2below:

                  TABLE 2                                                         ______________________________________                                               Coeff. of                                                                     Inplane           Glass     Number of                                         thermal Elastic   transition                                                                              Defective                                         expansion                                                                             modulus   temperature                                                                             parts (in                                         (X 10.sup.6 /K)                                                                       (kg · f/mm.sup.2)                                                              (° C.)                                                                           100 parts)                                 ______________________________________                                        Example 6                                                                              8.7       297       188     0                                        Example 7                                                                              8.5       290       195     0                                        Example 8                                                                              7.6       280       197     0                                        Example 9                                                                              8.0       282       202     0                                        ______________________________________                                    

According to the present invention, the coefficients of thermalexpansion of a laminate, a multilayer printed circuit board and aprepreg in the planar directions thereof are reduced along with theelastic moduli thereof, thereby making it possible to remarkably lowerthermal stresses which arise on packaging surfaces and to sharplyenhance the reliabilities of the connections of the laminate etc. witharticles or elements which are to be packaged.

Embodiment 10

A semiconductor device is obtained by mounting a semiconductor element11 formed of a silicon chip on a carrier substrate 14 shown in FIG. 4,which is a laminated plate (thermal expansion coefficient in a planardirection: 8.5 ppm/K) formed of varnish composed of 100 weight part ofepoxy compound (Dai-Nippon Ink Chemical Co.; EXA-1514), 88 weight partof phenol-novolak resin (Mitsui-Toyo Kouatsu Co.; XL223-3L), 10 weightport of amin-denaturated-dimethyl-piloxane (Chisso Co.; PS513) andE-glass cloth (thickness of 100 μm), by wiring using lead wires 12through wire bonding method, by molding the mounting surface with anencapsulating material 13 composed of an epoxy group resin (fillercontent: 82 volume percent, thermal expansion coefficient: 8.5 ppm/K),and by forming a solder ball grid array 15 on the mounting surface ofthe carrier substrate 14. The thermal expansion coefficientcharacteristic of said semiconductor device is shown in Table 3.

                  TABLE 3                                                         ______________________________________                                               THERMAL.      THERMAL                                                         EXPANSION     EXPANSION                                                       COEFFICIENT   COEFFICIENT                                                                              DIFFERENCE IN                                        OF            OF         THERMAL                                              ENCAPSULATING CARRIER    EXPANSION                                     EMBODI-                                                                              MATERIAL      SUBSTRATE  COEFFICIENTS                                  MENT   (ppm/K)       (ppm/K)    (ppm/K)                                       ______________________________________                                        10     8.5           8.5        ≈0                                    11     7.0           6.8        0.2                                           12     8.0           8.5        0.5                                           13     6.5           6.8        0.3                                           ______________________________________                                    

Embodiment 11

A semiconductor device is obtained by mounting a semiconductor element11 formed of a silicon chip on a carrier substrate 14, which is alaminated plate (thermal expansion coefficient in a planar direction:6.8 ppm/K) formed of varnish composed of 100 weight part of maleimidecompound (Mitsui-Toyo Kouatsu Co.; bis(4-maleimide-phenyl) methane), 38weight part of amine compound (Wakayama Fine Chemical Co.;2,2-bis(4-(4-amino-phenoxy)phenyl-propane), 5 weight part ofamin-denaturated-poly-dimethyl-siloxane (Toray Silicone Co.. Ltd.;SF8418) and T-glass cloth (thickness of 100 μm), by wiring using leadwires 12 through wire bonding method, by molding the mounting surfacewith an encapsulating material 13 composed of an epoxy group resin(filler content; 83.5 volume percent, thermal expansion coefficient: 7.0ppm/K), and by forming a solder bump ball grid array 15 on the mountingsurface of the carrier substrate 14. The thermal expansion coefficientcharacteristic of said semiconductor device is shown in Table 3.

Embodiment 12

As shown in FIG. 5, two layers of multi-wiring layer 16 usingpolyimide-copper wiring are formed on the surface of a semiconductorelement 11 through sequentially laminating method, and a solder ballgrid array 15 is formed in the outmost layer of the multi-wiring layer.This object is mounted on and electrically connected to a carriersubstrate 11 used in Embodiment 10, the mounting surface being moldedwith an epoxy group encapsulating material 13 (filler content: 83 volumepercent, thermal expansion coefficient: 8.0 ppm/K), a solder ball gridarray being formed on the mounting surface of the carrier substrate 14to obtain a semiconductor device. The thermal expansion coefficientcharacteristic of said semiconductor device is shown in Table 3.

Embodiment 13

A polyimide-copper wiring layer patterned is adhered on the surface of asemiconductor element 11, and another polyimide-copper wiring layerpatterned is adhered further thereon to-form a multi-wiring layer 16.Through holes are formed in the connecting portion of the layers byusing laser, the through holes being electrically connected with platingto form the multi-wiring layer (four conductive layer structure) 16. Asolder ball grid array is formed in the outmost layer of themulti-wiring layer through bump, being electrically connected to acarrier substrate 14 used in Embodiment 11, the mounting surface beingmolded with an epoxy group encapsulating material 13 (filler content: 84volume percent, thermal expansion coefficient: 6.5 ppm/K). Further, asolder ball grid array is formed on the mounting surface of the carriersubstrate 14 to obtain a semiconductor device. The thermal expansioncoefficient characteristic of said semiconductor device is shown inTable 3.

Embodiment 14

A semiconductor device shown in FIG. 6 is manufactured by mounting thesemiconductor device obtained in Embodiment on a mounting substrate 17formed of the same material as the resin composition used for thecarrier substrate 14 in Embodiment 10. Connecting reliability of thesemiconductor device has been studied by performing thermal cycle tests.The thermal cycle test is performed under the condition of 1000 times ofheat cycles of 150° C./10 minutes to -55° C./10 minutes. The thermalexpansion coefficient characteristic of the semiconductor device and theresult of the thermal cycle test are shown Table 4.

                                      TABLE 4                                     __________________________________________________________________________             THERMAL   THERMAL THERMAL THERMAL                                             EXPANSION EXPANSION                                                                             EXPANSION                                                                             CYCLE TEST                                          COEFFICIENT                                                                             COEFFICIENT                                                                           COEFFICIENT                                                                           (NUMBER OF                                          OF        OF      OF      FAILURE/                                            ENCAPSULATING                                                                           CARRIER MOUNTING                                                                              NUMBER OF                                           MATERIAL  SUBSTRATE                                                                             SUBSTRATE                                                                             TEST                                                (ppm/K)   (ppm/K) (ppm/K) SAMPLES)                                   __________________________________________________________________________    EMBODIMENT 14                                                                          7.0       6.8     8.5     0/10                                       EMBODIMENT 15                                                                          8.5       8.5     11.0    0/10                                       EMBODIMENT 16                                                                          6.5       6.8     7.0     0/10                                       REFERENCE 3                                                                            12.0      17.0    15.0    8/10                                       REFERENCE 4                                                                            8.0       11.0    11.0    2/10                                       __________________________________________________________________________

Embodiment 15

The semiconductor device obtained in Embodiment 10 is mounted on anepoxy group multi-layer substrate 17 (composing material; Shin-KoubeElectric Co. CEL-445, thermal expansion coefficient in a planardirection: 11 ppm/K), and the same thermal cycle test as in Embodiment14 is conducted to evaluate the connecting reliability. The thermalexpansion coefficient characteristic of the semiconductor device and theresult of the thermal cycle test are shown Table 4.

Embodiment 16

The semiconductor device obtained in Embodiment 13 is mounted on apolyimide group multi-layer substrate 17 (reinforcing material: alamidfiber (technola). CEL-445, thermal expansion coefficient in a planardirection: 7.0 ppm/K). and the same thermal cycle test as in Embodiment14 is conducted to evaluate the connecting reliability. The thermalexpansion coefficient characteristic of the semiconductor device and theresult of the thermal cycle test are shown Table 4.

Reference 3

A semiconductor element 11 is mounted on the carrier substrate 14 ofcommon FR-4 (ANSI (American National Standard Institute) standard),being connected with lead wires 12 by wire bonding method, being moldedwith an epoxy group encapsulating material 13 (filler content of 72volume percent). And a solder ball grid array is formed on the mountingsurface of the carrier substrate 14. With the semiconductor elementmounted on the FR-4 mounting substrate 17, the same thermal cycle testas in Embodiment 14 is conducted to evaluate the connecting reliability.The thermal expansion coefficient characteristic of the semiconductordevice and the result of the thermal cycle test are shown Table 4.

Reference 4

A semiconductor element 11 is mounted on the carrier substrate 14 of alow thermal expansion coefficient epoxy substrate, being connected withlead wires 12 by wire bonding method, being molded with an epoxy groupencapsulating material 3 (filler content of 80 volume percent). And asolder ball grid array is formed on the mounting surface of the carriersubstrate 14. With the semiconductor element mounted on the FR-4mounting substrate 17, the same thermal cycle test as in Embodiment 14is conducted to evaluate the connecting reliability. The thermalexpansion coefficient characteristic of the semiconductor device and theresult of the thermal cycle test are shown Table 4.

What is claimed is:
 1. A laminate capable of mounting one or moresemiconductor elements thereon, comprising an insulating layerexhibiting a coefficient of thermal expansion of 3.0˜10 (ppm/K) in aplanar direction thereof and a glass transition temperature of 150°-300°C.,said insulating layer comprising a resin portion of a sea-islandstructure and a woven reinforcement, said resin portion comprising afirst resin and an organic compound filler dispersed therein, saidorganic compound filler forming with said first resin a phase separationstructure as said sea-island structure.
 2. The laminate of claim 1wherein said resin portion further comprises an inorganic fillerdispersed therein.
 3. The laminate of claim 1 wherein said first resincomprises a thermosetting resin, and said organic compound fillercomprises an organic compound selected from the group consisting of asiloxane-containing compound, a polymer of a siloxane-containingcompound, a fluorine-containing compound, and a polymer of afluorine-containing compound.
 4. The laminate of claim 2 wherein saidresin comprises a thermosetting resin, and said organic compound fillercomprises an organic compound selected from the group consisting of asiloxane-containing compound, a polymer of a siloxane-containingcompound, a fluorine-containing compound, and a polymer of afluorine-containing compound.
 5. The laminate of claim 1 wherein saidfirst resin comprises a resin selected from the group consisting ofepoxy resin, unsaturated polyester resin, epoxy-isocyanate resin,maleimide resin, maleimide-epoxy resin, cyanate-ester resin,cyanate-ester-epoxy resin, cyanate-ester-maleimide resin, phenolicresin, diallyl-phthalate resin, urethane resin, cyanamide resin, andmaleimide-cyanamide resin.
 6. The laminate of claim 1 wherein saidorganic compound filler comprises a second resin selected from the groupconsisting of a polymer of perfluoro-ether, poly-tetrafluoro-ethylene,copolymers of poly-tetrafluoroethylene and perfluoro-alkylvinyl-ether, acopolymer of tetrafluoroethylene and hexafluoro-propane,polychlorotrifluoro-ethylene, a copolymer of ethylene andtetrafluoro-ethylene, polyvinylidene fluoride, and polyvinyl fluoride.7. The laminate of claim 6 wherein said first resin comprises an epoxyresin, and said organic compound filler comprises a polymer ofperfluoro-ether.
 8. A prepreg comprising a resin portion of a sea-islandstructure and a woven reinforcement impregnated with said resin portion,said prepreg exhibiting a coefficient of thermal expansion of 3.0-10(ppm/K) in a planar direction thereof and a glass transition temperatureof 150°-300° C., said resin portion comprising a first resin and anorganic compound filler dispersed in said first resin, said organiccompound filler forming with said first resin a phase separationstructure as said sea-island structure.
 9. A memory card comprising acircuit board and a memory device mounted on said circuit board, whereinsaid circuit board comprises an insulating layer exhibiting acoefficient of thermal expansion of 3.0-10 (ppm/K) in a planar directionthereof and a glass transition temperature of 150°-300° C.,saidinsulating layer comprising a resin portion of a sea-island structureand a woven reinforcement, said resin portion comprising a first resinand an organic compound filler dispersed therein, said organic compoundfiller forming with said first resin a phase separation structure assaid sea-island structure.
 10. A resin encapsulated semiconductordevice, comprising:a semiconductor element, an encapsulated materialcovering said semiconductor element, a carrier substrate for mountingsaid semiconductor element thereon, and, connecting terminals formed ofsolder balls on the surface opposite to the mounting surface of saidcarrier substrate, wherein:said carrier substrate comprises a resinportion of a sea-island structure and a woven reinforcement, said resinportion comprises a first resin and an organic filler dispersed therein,said organic filler forms with said first resin a phase separationstructure as said sea-island structure.
 11. The resin encapsulatedsemi-conductor device of claim 10, wherein said resin portion has anelastic modulus lower than that of said woven fiber reinforcement. 12.The resin encapsulated semiconductor device of claim 10, wherein saidfirst resin has an elastic modulus larger than that of said organicfiller and lower than that of said woven reinforcement.
 13. A resinencapsulated semi conductor device, which comprises:a semiconductorelement, an encapsulant material covering said semiconductor element, acarrier substrate for mounting said semiconductor element thereon, andconnecting terminals formed of solder balls on the surface opposite tothe mounting surface of said carrier substrate, wherein:said carriersubstrate comprises a laminate of claim
 1. 14. The resin encapsulatedsemiconductor device comprising the laminate of claim
 2. 15. The resinencapsulated semiconductor device comprising the laminate of claim 3.16. The resin encapsulated semiconductor device comprising the laminateof claim
 4. 17. The resin encapsulated semiconductor device comprisingthe laminate of claim
 5. 18. The resin encapsulated semiconductor devicecomprising the laminate of claim
 6. 19. The resin encapsulatedsemiconductor device comprising the laminate of claim 7.